56. Solving a chemistry problem

17. Construct curves of potentiometric titration in the coordinates E – V and E∆/∆V – V and determine the concentration of MgBr2 in the solution (g/l), if during titration of 20.0 ml of the analyzed solution 0.10 N Hg2(NO3)2 ( fequiv = 1/2) received:
V(Hg2(NO3)2), ml 10.00 15.00 18.00 19.00 19.50 19.90 20.00 20.10 20.50
E, mV 501 526 552 570 589 629 704 737 757